1. Field of Invention
The present invention relates to agents having regulatory activity for the morphological transition of dimorphic fungi which can grow both as yeast form cells and as mycelial form cells.
2. Description of Related Art
Most fungi take the form, through their life cycle, of either a spherical single cell growing through budding (or cell division) (yeast form fungus) or a filamentous multicellular organism growing through apical growth (filamentous fungus). However, some yeasts can reversibly take yeast form (Y form) and mycelial form (M form). This phenomena in which such a reversible transition occurs due to a specific nutritional, physical or chemical factor is called as dimorphism. The dimorphic fungi generally belong to Subdivision Deuteromycotina. and typically include genus Candida. The dimorphic fungi such as genus Candida are indigenous microbes with respect to humans, which generally exist in human bodies or in a living environment. They are not pathogenic to healthy humans but become pathogenic to patients whose immunity is deteriorated by some cause, and such an infection is called as an opportunistic infection. By taking Candida albicans belonging to genus Candida as an example, it has been known, in fact, that a multiplicity of mycelial form cells are present in combination with yeast form cells in infectious foci of candidiasis, indicating that being mycelial form cells is one of the pathogenic factors of this fungi. This is supposedly because mycelia of the mycelium form cells readily adhere to animal tissues and advantageously serve to invade mechanically into the inside of host tissues, and in addition hardly suffer from mycophagy activities of phagocytes (Arai, T., et al., Sabouraudia 15, 171-177(1977)).